Most late filings in small businesses are not caused by hard accounting. They are caused by the VAT return being started on the day it is due because nobody wrote down that it was due. A close calendar fixes that: one schedule that says which task happens on which working day after month end, who does it, and which statutory deadlines fall in the coming months.
Build the monthly calendar in working days
Express tasks as working days after month end (WD1, WD2…), not dates. The calendar then works for every month without being rewritten.
| Day | Task | Depends on |
|---|---|---|
| Last working day | Raise all sales invoices for work done in the month; payroll processed | Timesheets, delivery notes |
| WD1 | Bank feeds matched to the last day; card statements imported | Bank access |
| WD1–WD2 | Purchase invoices for the month entered; supplier statements reconciled | Invoices received |
| WD2 | Payroll journal posted; pension and PAYE liabilities checked | Payroll run |
| WD3 | Accruals, prepayments and depreciation posted | Purchase ledger complete |
| WD3 | Balance sheet reconciliations: bank, debtors, creditors, VAT, payroll | All postings above |
| WD4 | Management accounts produced and reviewed | Reconciliations complete |
| WD5 | Owner review meeting; period locked | Management accounts |
The order matters more than the exact day. Accruals cannot be judged until the purchase ledger is complete; reconciliations are pointless until the journals are in; the period should only be locked once the owner has seen the numbers.
A five-day close is realistic for most small businesses using bank feeds. If yours takes three weeks, look for the step everyone waits on, which is usually missing purchase invoices.
Plot the statutory deadlines
Next to the working-day plan, keep a rolling twelve-month list of filing and payment deadlines. These are the ones most UK small companies face; confirm the rules for your own business on gov.uk, because some depend on size, payment method and scheme.
| Obligation | Rule | Frequency |
|---|---|---|
| VAT return and payment (Making Tax Digital) | Normally 1 calendar month and 7 days after the end of the VAT period | Quarterly for most businesses |
| Full Payment Submission (payroll) | On or before each payday | Every pay run |
| Employer Payment Summary | By the 19th of the following tax month, when needed | Monthly when there is something to report |
| PAYE and NIC payment | By the 22nd of the following tax month if paid electronically | Monthly (quarterly for some small employers) |
| Corporation tax payment | 9 months and 1 day after the end of the accounting period, for companies that are not large | Annually |
| Company Tax Return (CT600) | 12 months after the end of the accounting period | Annually |
| Annual accounts to Companies House | 9 months after the accounting reference date for a private company (first accounts follow a different rule) | Annually |
| Confirmation statement | Within 14 days after the end of the review period | At least once every 12 months |
The calendar view of these, with how each is calculated, is in key UK filing deadlines. Note that the corporation tax payment falls before the return is due: plan to know your tax figure in time to pay it.
Work backwards from each deadline
For each deadline, write the internal date by which the work must be finished, and put that date in the calendar instead of the statutory one:
- VAT return: the quarter’s last monthly close plus two working days for review. If the VAT period ends on 31 March, the books for March should be closed and the return reviewed long before the May due date.
- Year-end accounts: agree with your accountant when they need the year-end file. Working back from the Companies House deadline, many small companies aim to hand over within two to three months of the year end.
- Corporation tax: a draft computation at least a month before the payment date, so the cash can be set aside.
Year-end adds a second layer
The year-end close is a normal month-end plus extra tasks: stock count, fixed asset review, provisions, bad debt review, and the handover to the accountant. Put those into the calendar for the last month of the year as their own working days, and start the stock count arrangements and fixed asset review before the year end, not after. The year-end checklist lists them.
Keep the calendar alive
- Name an owner for every line, and a back-up for holidays.
- Review it each quarter: new VAT schemes, a change of year end or a new payroll frequency all change the dates.
- Record what actually happened: if WD3 keeps becoming WD6, the problem is upstream and the calendar shows exactly where.